The present inventions relate to apparatus and methods for affecting a patient""s body temperature, particularly for therapeutic applications. There are broader applications, such as with heating pads and the like and in any application in which there is a need to reduce or prevent heat/moisture build-up between a person""s body and a support surface with which the patient""s body is in contact, but the present inventions relate primarily to cooling pads and systems for lowering a patient""s body temperature. Intended fields include applications for patients with diminished health and for patients using therapeutic supports such as oscillating treatment platforms, pressure reducing mattresses, and low air loss beds, to name a few.
Various types of devices have long existed for cooling and heating patients without much regard for accommodating other health care needs. Such devices typically use a heat exchanger in a form of a flexible pad that can be positioned close to the patient""s skin. Because of the way such pads work, they have traditionally been fluid impervious, which can trap moisture (i.e., condensation, sweat, incontinence, etc.) in close proximity to a patient""s skin.
High moisture levels, however, tend to promote maceration and skin-breakdown. To make matters worse, the lower temperatures induced by cooling pads might naturally constrict a patient""s capillaries, which may reduce the flow of oxygen and nutrients to the skin. Such effects would be of particular concern in patients who have poor skin condition or compromised circulation from the start. Hence, conventional cooling pads may create an environment that is less than ideal for skin care.
For many of the same patient populations, there have also long been many types of specialized patient supports adapted to facilitate skin care. Two notable types of specialized therapeutic supports are (i) pressure reducing mattresses for reducing the pressures exerted by a mattress against a patient""s skin (referred to as xe2x80x9cinterface pressuresxe2x80x9d), and (ii) oscillating treatment platforms for rotating patients from side-to-side. (For present purposes, low air loss mattresses and other pressure relieving mattresses are grouped together with pressure reducing mattresses.) Commercial examples of pressure reducing mattresses are available through KCI Therapeutic Services, Inc. of San Antonio, Tex., under the THERAREST(trademark) (for composite foam mattresses) and FIRST STEP(trademark) (for low air loss mattresses) trademarks. Detailed descriptions of particular pressure reducing mattresses may be found in U.S. Pat. No. 5,022,110 issued Jun. 11, 1991 (Stroh) and U.S. Pat. No. 3,644,950 issued Feb. 29, 1972 (Lindsay).
Oscillating treatment platforms are useful in treating and/or preventing a wide range of illnesses and conditions. Such a platform is particularly useful in addressing complications that may be encountered with immobile patients, including bed sores and other skin problems. By automatically rotating the patient from one lateral side to the other on a periodic basis, interface pressures at any particular location are likewise varied. As always, though, excess moisture near the patient""s skin site tends to increase the likelihood of further skin problems. Commercial examples of oscillating treatment platforms are available through KCI Therapeutic Services, Inc. of San Antonio, Tex., under the ROTO REST(trademark) trademark. Particular examples are also described in U.S. Pat. No. 3,343,165 issued on Mar. 25, 1969 (Keane) and U.S. Pat. No. 4,175,550 issued on Nov. 27, 1979 (Leininger et al.).
The descriptions (including drawings) of each of the above patents and all other patents referenced elsewhere in this application are incorporated herein by this reference, as though set forth in their entirety.
Despite the importance and high costs of skin care, the need to use hyper and/or hypothermia pads often overrides any concerns about the moist skin climate often associated with use of such pads. As a consequence, the therapeutic benefits of a patient""s specialized support may be diminished. Consider low air loss (xe2x80x9cLALxe2x80x9d) mattresses, for instance. Perhaps the most important benefit of a LAL mattress is the slow but continuous evacuation of moisture vapor from adjacent the skin. Typical LAL mattresses support the patient with air cushions made from vapor-permeable fabrics. The vapor permeable material allows moisture vapor near the skin to pass away from the skin, and a continuous flow of air keeps the cushions inflated while also evacuating the moisture vapor that has passed through the fabric. Such benefits are significantly impeded by introducing a cooling pad which is impervious to fluid between the patient and the air cushions of the LAL mattress.
As can be seen, although numerous specialized patient supports are generally useful in minimizing skin breakdown and in otherwise treating or preventing various ailments, there remains a need to improve such products and the conditions under which they may be used. There is also a therapeutic as well as a comfort need to improve thermal pads and the environments in which they are used.
It is a basic object of the present inventions to promote patient health by improving available therapies. This object may be addressed in part by improving devices for patient temperature control, such as by improving the functionality, efficiency, ease-of-use, comfort, safety and effectiveness of such devices.
It is another basic object to improve patient supports, particularly by enabling patient temperature control as an adjunct to other benefits of patient supports. It is a related object to enable patient temperature control using cooling pads and the like without compromising patient skin condition or impeding other therapies, including low air loss therapy and continuous lateral rotation therapy.
Accordingly, the present invention is directed in part to patient temperature control on a patient support. Such control may include use of a thermally controlled sheet (such as a pad or blanket) through which a heat transfer fluid is circulated. The sheet typically defines two types of passagesxe2x80x94an enclosed array of fluid passages for directing the heat transfer fluid, and cross passages or the equivalent for passage of other fluids from one face of the sheet to the other. As gas passages, the cross passages permit air and/or moisture vapor to pass from one side of the sheet to the other, thereby addressing many objects including the object of enabling the provision of thermal control as an adjunct to low air loss therapy. As an open hole or the like through the thermal sheet, the cross passages may also permit liquids such as condensation, sweat, body fluids, etc. to pass away from a patient""s skin, thereby minimizing maceration and skin breakdown.
Embodied as an under-patient pad, one face of the sheet faces the patient while the opposite sheet faces the patient support. The sheet is typically formed by welding the two faces together in a way that forms a plurality of pocket passages therebetween. Liquid and/or vapor cross-passages or other types of openings are formed between the pocket passages. Lines are provided to operably connect the pocket passages with a conventional hyper-hypothermia unit to permit fluid flow therethrough and the sheet is welded at intervals forming the fluid passages which are spaced and arranged so as to direct the flow of fluid therethrough throughout the entire sheet. Hook and pile tabs and/or other fasteners are provided at opposite ends of the pad for anchoring or for combining the pad with other similar pads to affect a larger surface area and on the side edges of the pads for securing the pad to a patient support surface.
The thermal control sheet may be configured to wrap around at least a part of the patient in certain applications. Alternating flows may also be used. The invention also includes various therapeutic methods for facilitating patient care.
Many objects and advantages will be readily apparent to those skilled in the art upon viewing the drawings and reading the detailed description hereafter, particularly when considered in light of the appended claims and the related art.